Indoor boomerang



FIG. 1 is a top plan view of an indoor boomerang, showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a side elevational view thereof, taken from side "A"; and,

FIG. 4 is a side elevational view thereof, taken from side "B". 

The ornamental design for an indoor boomerang, as shown. 